One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(6,9)(7,11)(15,16)(17,19)(21,22)(23,24)(25,28)(26,27) involution — undirected(5,6)(7,10)(8,9)(11,12)(13,14,18,20)(15,19,16,17)(21,22,25,28)(23,24,27,26)(5,6)(7,10)(8,9)(11,12)(13,15,18,16)(14,19,20,17)(21,23)(22,26)(24,28)(25,27)(1,2,3,4)(5,6)(7,12)(8,9)(10,11)(13,16,18,15)(14,17,20,19)(21,23)(22,24)(25,27)(26,28)(5,7)(6,10)(8,11)(9,12)(13,17)(14,15)(16,20)(18,19)(21,24)(22,27)(23,28)(25,26) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.